For the beam splitter attack strategy against quantum key distribution using two-mode squeezed states, the analytical expression of the optimal beam splitter parameter is provided in this paper by applying the Shannon...For the beam splitter attack strategy against quantum key distribution using two-mode squeezed states, the analytical expression of the optimal beam splitter parameter is provided in this paper by applying the Shannon information theory. The theoretical secret information rate after error correction and privacy amplification is given in terms of the squeezed parameter and channel parameters. The results show that the two-mode squeezed state quantum key distribution is secure against an optimal beam splitter attack.展开更多
在可再生能源高渗透率的背景下,电力系统的负荷频率控制(load frequency control,LFC)面临虚假数据注入攻击(false data injection attack,FDIA)的安全威胁。现有检测方法难以有效区分控制输入攻击和测量数据攻击,影响系统的稳定性和安...在可再生能源高渗透率的背景下,电力系统的负荷频率控制(load frequency control,LFC)面临虚假数据注入攻击(false data injection attack,FDIA)的安全威胁。现有检测方法难以有效区分控制输入攻击和测量数据攻击,影响系统的稳定性和安全性。为此建立了包含可再生能源及储能系统的LFC状态空间模型,并分析了FDIA对系统动态特性的影响。通过状态空间分解方法将攻击信号解耦为控制输入攻击和测量攻击,提高检测精度。基于滑模观测器设计攻击估计方法,实现对攻击信号的实时检测。进一步结合H∞控制理论,提出了抗攻击控制(attack-resilient control,ARC)策略,以增强系统在攻击环境下的鲁棒性。仿真算例表明:与传统方法相比攻击估计均方误差降低约30%,系统频率响应稳定性显著提升。结果表明,该方法能够有效检测FDIA并提高电力系统的安全性和抗干扰能力。展开更多
This paper analyses the issue of impact time control of super-cavitation weapons impact fixed targets which mainly refer to the ships or submarines who lost power, but still have combat capability. Control over impact...This paper analyses the issue of impact time control of super-cavitation weapons impact fixed targets which mainly refer to the ships or submarines who lost power, but still have combat capability. Control over impact time constraints of guidance law(ITCG) is derived by using sliding mode control(SMC) and Lyapunov stability theorem. The expected impact time is realized by using the notion of attack process and estimated time-to-go to design sliding mode surface(SMS). ITCG contains equivalent and discontinuous guidance laws, once state variables arrive at SMS,the equivalent guidance law keeps the state variables on SMS,then the discontinuous guidance law enforces state variables to move and reach SMS. The singularity problem of ITCG is also analyzed. Theoretical analysis and numerical simulation results are given to test the effectiveness of ITCG designed in this paper.展开更多
基金Project supported by the Shanghai Jiaotong University (SJTU) Young Teacher Foundation,China (Grant No A2831B)the SJTU Participating in Research Projects (PRPs),China (Grant No T03011030)the National Natural Science Foundation of China(Grant No 60472018)
文摘For the beam splitter attack strategy against quantum key distribution using two-mode squeezed states, the analytical expression of the optimal beam splitter parameter is provided in this paper by applying the Shannon information theory. The theoretical secret information rate after error correction and privacy amplification is given in terms of the squeezed parameter and channel parameters. The results show that the two-mode squeezed state quantum key distribution is secure against an optimal beam splitter attack.
文摘在可再生能源高渗透率的背景下,电力系统的负荷频率控制(load frequency control,LFC)面临虚假数据注入攻击(false data injection attack,FDIA)的安全威胁。现有检测方法难以有效区分控制输入攻击和测量数据攻击,影响系统的稳定性和安全性。为此建立了包含可再生能源及储能系统的LFC状态空间模型,并分析了FDIA对系统动态特性的影响。通过状态空间分解方法将攻击信号解耦为控制输入攻击和测量攻击,提高检测精度。基于滑模观测器设计攻击估计方法,实现对攻击信号的实时检测。进一步结合H∞控制理论,提出了抗攻击控制(attack-resilient control,ARC)策略,以增强系统在攻击环境下的鲁棒性。仿真算例表明:与传统方法相比攻击估计均方误差降低约30%,系统频率响应稳定性显著提升。结果表明,该方法能够有效检测FDIA并提高电力系统的安全性和抗干扰能力。
基金supported by the National Natural Science Foundation of China(5137917651679201)
文摘This paper analyses the issue of impact time control of super-cavitation weapons impact fixed targets which mainly refer to the ships or submarines who lost power, but still have combat capability. Control over impact time constraints of guidance law(ITCG) is derived by using sliding mode control(SMC) and Lyapunov stability theorem. The expected impact time is realized by using the notion of attack process and estimated time-to-go to design sliding mode surface(SMS). ITCG contains equivalent and discontinuous guidance laws, once state variables arrive at SMS,the equivalent guidance law keeps the state variables on SMS,then the discontinuous guidance law enforces state variables to move and reach SMS. The singularity problem of ITCG is also analyzed. Theoretical analysis and numerical simulation results are given to test the effectiveness of ITCG designed in this paper.
文摘传统联邦学习训练模型时假定所有参与方可信,但实际场景存在恶意参与方或恶意攻击模型,现有的联邦学习算法面对投毒攻击时,存在模型性能严重下降的问题。针对模型投毒问题,本文提出一种基于联邦平均(federated averaging,Fedavg)与异常检测的联邦检测算法——FedavgCof,该算法考虑到所有参与方之间的差异对比,在中心服务器和本地模型之间添加异常检测层,通过基于聚类的本地异常检测因子(cluster-based local outlier factor,COF)异常检测算法剔除影响模型性能的异常参数,提升模型鲁棒性。实验结果表明,虽然新型投毒方式攻击性更强,但是FedavgCof能够有效防御投毒攻击,降低模型性能损失,提高模型抗投毒攻击能力,相较于Median和模型清洗算法平均提升精度达到10%以上,大幅提升了模型的安全性。
